Electrical conductor



(NqModeL) G. GRAY. ELECTRICAL CONDUCTOR.

Patented Aug. 6

7 Z M g p? WITNESSES.

UNIT D STATES PATENT Orrrct GORHAM GRAY, OF BOSTON, MASSACHUSETTS, ASSIGNOR TO THE SPIRAL WIRE COMPANY, OF PORTLAND, MAINE.

ELECTRICAL CONDUCTOR.

SPECIFICATION forming part of Letters Fatent No. 543,960, dated August 6, 1895.

Application filed December 14,1894. Serial Nol 531,791. (No model.)

To all whom it may concern.-

Be itknown that I, GORHAM GRAY, a citizen of the United States, and a resident of Boston, in the county of Suffolk and State of Massachusetts, have invented certain new and useful Improvements in Electrical Conductors; and I do hereby declare that the following is a full, clear, and exact description of the invention, which will enable others skilled in the art to which it appertains to make and use the same, reference being had to the accompanying drawings, which form a part of this specification, and in which Figure 1 is a perspective view of a short piece of my improved conductor. Fig. 2 is a side view of the same; and Fig.3 is a transverse sectional view of my improved conductor on line a: a; in Fig. 2, on an enlarged scale.

Like letters of reference designate corresponding parts in all the figures.

This invention relates to conductors for electrical currents of all kinds where it is of importance to overcome induction; and it consists in an improved antiinductive wire of the construction which will be hereinafter more fully described and claimed.

Referring to the drawings, the letter A denotes the body of a metal conductor or wire of any desired metal and dimensions according to the purpose for which it is to be used. The outside of this conductor or wire is grooved spirally in two opposite directions-that is to say, it has one or more right-hand spiral groove or grooves a, encircling the wire from end to end, and another left-hand spiral groove or series of grooves b, also extending from one end of the wire to the other, so as to intersect or cut across the spirals Ct at each twist or turn, as clearly illustrated on the drawings. Both of these intersecting spiral grooves or series of grooves a and b are preferably of the same depth and pitch, and may be produced by suitable machines, either byindenting the body of the wire A or by cutting out a portion of the metal on the surface. 'I have, however, constructed and prefer to use a machine intended specifically for the cross-grooving of the wire in such a manner as to attain the best and most satisfactory results, which will form the subject of a separate application.

I am aware that an antiinductive conductor for telegraph and telephone lines, consisting of a Wire grooved spirally in one direction is not new, I, myself, being the inventor and patentee of such a device as described and claimed in my Letters Patent of the United States No. 290,769, hearing date of December 25, 1883; but I have found by a long and exhaustive series of tests and ex periments that While the in one direction spiraled device is a great improvement upon the ordinary plain wire usually employed for telegraph and telephone lines my improved cross-spiraled conductor possesses still greater advantages as an antiinductive device, and. may be used in telegraph and telephone lines in systems and under conditions (due, for example, to the proximity of electric-lightw1res or trolley-wires carrying high-tension currents) where an ordinary wire would be ren- V dered utterly useless.

I desire it to be understood that this improvement is not limited in its application to wires for telegraph and telephone lines, but may be advantageously introduced and adopted for electrical conductors generally; hence What I claim as my invention, and desire to secure-by Letters Patent of the United States, is-

As an improved article of manufacture, an anti-inductive conductor for electric currents consisting of a wire grooved spirally in opposite directions, so that the spirals will intersect or cut across one another at each turn or twist around the wire; substantially as set forth.

In testimony that I claim the foregoing as my own Ihave hereunto affixed my signature in presence of two witnesses.

GORHAM GRAY.

Witnesses:

HARRIETTE WEBB GRAY, M. D. GRAY. 

